When it interferes with a discussion of Halakah; see Bab. Mesia' 59 b.
By giving it precedence over the benediction over wine.
I.e. after the meal, over the cup of wine he says Grace, the benediction over the wine, light, spices and Habdalah, the last-named corresponding to "the benediction of the day." Consequently "the benediction of the day" comes last and not first as was stated above.
On the next folio, p. 337, it is stated that according to R. Meir, the point at issue is not the order of light and spices, but the benediction over the food ; consequently the quoted Baraita could be Bet Hillel's teaching.
To connect the Baraita with our Mishnah.
The Mishnah places the benediction over food, according to both Schools, in the middle, whereas the Baraita allows it to come first. We have, therefore, to depend upon the difference of the two Schools in the version of R. Judah, viz. the order of light and spices, according to which the Baraita agrees with Bet Shammai.
According to the Mishnah, Bet Shammai require the benediction over the day before that over the wine ; but according to the Baraita (which it is concluded emanates from Bet Shammai) the benediction over the wine precedes the Habdalah.
The advent is marked by the benediction over the day, therefore it should come first, and it is to that the Mishnah refers.
The conclusion is marked by the Habdalah and should come last. Since the baraita refers to the conclusion of the holy day, it does not conflict with the Mishnah.
The Barita stated : "Should he have only one cup of wine, he leaves it until after the meal and combines all [the benedictions] afterwards," i.e. wine is required for Grace. But according to the Mishnah, if wine is brought to the man after he has eaten, so that he has not yet said a benediction over wine, he does so over this cup, drinks it and then says Grace; therefore wine is not essential for the Grace.
I.e. dips his finger in the wine, which he then puts to his mouth.
According to the Tanna of the Mishnah, i.e. R. Judah, Bet Shammai require wine for Grace ; but R. Hiyya understands them as not requiring it.
Liquid is the conductor of defilement for food ; cf. Lev. xi. 34.
Without the medium of a liquid; so why this fear?
Contracting defilement from something else.
Even if the hands are not moist.
Unless it be unclean in the first degree.